The present invention relates to either measuring machines or layout machines in which horizontal and vertical measurements are necessary.
Such machines may be of the type shown in U.S. Pat. No. 3,129,512 or 3,379,077. A machine operator positioned adjacent the machine advantageously reads horizontal and vertical measurements from a single location preferably quickly and with a minimum possibility for error. From a single operator's vantage point the reference numerals must be easily read and clearly understood (which reference numerals correspond to which of the measurement indicia) for quick and accurate machine use.
In the past, such machines have used at least two different sets of scales and verniers, one in which the height of reference numerals are arranged perpendicular to the lead lines for a vertically-extending scale and one in which the height of reference numerals are generaly aligned with the lead lines for a horizontally-extending scale. Since such a system requires at least two different sets of scales (and verniers) for the two different axes of measurement, it is undesireable in that it requires a stocking of a plurality of parts, each of which has to be separately manufactured and inventoried. In some machines, a third type of vernier and scale are required to read a third direction (depth).
The presence of similar-appearing scales for different applications (axes) presents a possibility for mismounting the scales and verniers (i.e., an x-axis scale mounted on a y-axis, etc.). In prior art machines, a mismounting of scales of this type would make readings substantially more difficult for the operator.
Since the measurement and layout machines of the present invention are manufactured in a variety of sizes, and since each different size of machine might require a different size of scale, a system which requires multiple (two or more) sets of scales for each machine (i.e., different scales for each axis) is significantly less desirable than a system which requires one.
Some prior art measuring devices such as protractors have used reference numerals which are inclined or canted. This is either to present a stylized version of numbers or in which the reference numerals have a arrangement which varies throughout a curved scale to provide a common orientation of the numerals carried on a single measuring device. In such devices, there is generally only one location of a measuring scale. The prior art is not known to have provided interchangabile scales. Examples of prior art patents which were identified in a search on the present invention include U.S. Pat. Nos. 2,701,417; 3,116,556; 3,328,883; 3,531,865; and 4,159,571.
Accordingly, the foregoing prior art systems lack a universal measurement scale (or vernier) of the type which could be conveniently mounted in either a horizontal or vertical orientation or arrangement and yet be easily read by an operator. The prior art systems also lack interchangable measurement scales suitable for mounting in either a horizontal or vertical arrangement.